US elections have not always been held on Tuesdays. Due to rampant corruption, Congress needed to pick a standard date for presidential and vice presidential elections to occur uniformly throughout the country. Tuesday was chosen as that day in 1845 due to the farming lifestyle and traveling issues that faced people in those times.
From 1792 through 1844, Congress allowed states to have their US elections for president and vice president to occur any day between the first Wednesday of December and 34 days prior to that day. The first Wednesday in December was the day when the Electoral College met and all the votes needed to be cast and counted prior to then. During those years, US elections were held on various days, depending on the state.
Having elections on different days in different states led to corruption. Politicians and political parties would send people state-to-state to vote, which resulted in people voting numerous times. This was done to influence tight elections as the December deadline loomed. Holding US elections on different days also meant that the states which had their elections last were often influenced by the results of the earlier states.
In 1845 Congress declared that the first Tuesday after the first Monday in November as US election days for the office of President and Vice President. They had opted for early November because that still allowed enough time for vote counting before the Electoral College met in December. November was after the harvest that kept most farmers too busy earlier in the year. Early November also meant less likelihood of snow causing travel burdens.
Tuesday was chosen due to the extensive travel, at least one day, that faced many farming Americans trying to get to the county seat to vote. Congress could not choose the days surrounding Sundays for US elections since people were at church honoring the Sabbath and could not be traveling those days. This meant Saturday, Sunday and Monday were all not options.
In many towns, Wednesdays were market days so voters needed to be back at their home towns on those days so they could purchase and sell goods. Therefore Wednesdays and Thursdays would not work. Tuesdays were an option because a voter could travel on Monday, vote first thing on Tuesday and be back for market Wednesdays. In 1872 Congress determined that all congressional elections occur on that same Tuesday and this has not changed the US election day since then.